Calipering-gage for screw-threads.



F. 0. WELLS 6; k'. JUDGE.

CALIPERING GAGE POR SCREW THREADS,

APPLICATION FILED JUNE 19, 1913.

Patented Maz', 17, 1914 HBHEIZTSnSHEET l.

E. U. WELLS L F. JUDGE.

CALIPBRNG GAGE POR SCREW THREADS.

APPLIUATION FILED JUNE 19, 1913.

F. 0. WELLS L F. JUDGE.

CALIPEEING GAGE EUR SCREW THREADS.

APPLIOATlON FILED JUNE l', 1913,

Patented Mar. 17, 1914.

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UNITED sfrazrns CALIPERING-GAGE FOR SCREW-THREADS.

PATENT UFFICE.

Specification of 'Letters Patent.

Patented Mar. 1,7, 1914.

Application filed June 19, 1913. Serial No. 774,576

To all 1li/0m -it may conce-rn.;

Be it known that we, F RANK O. iVELLs and FRANKLIN JUDGE, citizens ofthe United States of America, residing at Greeneld, in the county ofFranklin and State. of Massa.- chusctts, have invented new and usefulImprovements in Calipering-Gages for`ScreW- Threads, of which thefollowing is a specification.

This invent-ion relates to improvements 1n calipering or Agage devicesfor measuring or comparing the pitch and the diameters of threads.

The object of the invention is to `quickly -and accurately determine thevaria-tien in pitch and diarneter'o the threads measured. The nut of abolt will not accurately tit unless the pitch or lead ofthe screw isequal in bot-h elements.

Broadly,the invention consists in the cembination of a standard threadedelement together with a movable measuring device.,`

Set the apparatus is threaded to measure per fectly with the threads ofthe first-named standard threaded'element, and the measuring device isdesigned to enter one of the teeth of the second-mentioned `standard ina diametrically opposite position. VVit-h the apparatus thus set, anythreaded element can be compared with the standard by resting itsquarely between the standard threaded element and the n'iovablemeasuring device. It there is 'variation in the threads of'the elementconquered or in the diameter of that element r both, the movablemeasuring device a position indicating the degree i as compared to thestandard. threaded element which is a pitch either l auth-rrd pitch andan the standard sary to have sec- .hin minimum limsmall-sized element ikth cannot pese.

By means of this apparatus, threaded elements that do not vary in sizewithin the prescribed or desired limits of accuracy are quickly sortedfrom those having the desired accuracy, and it is not necessary to haveSkilled labor in making these very accurate' comparisons.

vIn the drawings, Figure l is a plan view showing the adjustable combmember and the movable element to which the pointer is attached. Fig. 2is a, vertical sectional View on the line 2-2 of Fig. l, showing inside. elevation the comb or standard threaded member and the movablemember. It also shows a vertically-movable platform on which the threadto be measured this platform being adjhstable for threads' of diiierentdiameters. Fig. 3 is a. plan. View of a, modification in ivhieh two sets.of combmembers are used instead of as in Fig.A 1, where one is a comband the other a movable done-shaped member. Fig. 4 isa verticalsectional view of a further modification showing the two sets of gagedevices, it being understood that in Figs. 3 and 4 a 'pointer is lisedto indicate the V size ofthe thread being measured, asshown in Fig. 1,-the construction shown in this figure being designed to indicate themaximumand minimum sizes. Fig. 5 is 'a plan view .of a furthermodification in which a micrometer is used instead of a pointer. Fig. 6is a sectional view on the line G-6 of Fi 5.

Referring to the drawings, a` esignates the base-portion of theinstrument, and mounted in the-arm b is a movable combmember c which issecured to a rod d; located back of the rod d is an adjustingscrew ehaving a lmurlcd head'f. By rotating the bead f the comb member o can beadjusted. 'lhisI comb is provided With teeth c1 to receive the thread ofthe screw that is to be measured. The teeth Vc' of thecomb c areaccurately formed with relation to the standard and thread and it may,therefore, be considered a standard thread itself. L0- cated oppositelyto the arm-member I) is a second armanember g in which mounted a sii.able conc or measuring element It which is .iocated in line with thestandard combmember c, and arranged back of this coneniember /L is anadjusting-screw z', and between the screw z' and the outer end of the isplaced,

Y or zero Arrange( in the base-p'ortlon of the instrucone-member h is acoiled compressionspringl j, the purpose of which is to auto maticallymovethe'conemember h inward .toward the comb-member c.

In order'to limit the forward movement to rece-ive the rounded end s ofthe pointerl This pointer is arranged to -swing over a scale u and 1snormally -held in its center osition by means of. a spring o;

ment` is a vertically-movable table 'w on which the thread to bemeasured is placed4 s0 that the axis of the thread i's parallel with thecontact members. This table is secured .to a depending portion a: inwhich is formed a recess mi to receive'an elevating spring y, the lowerend of which rests upon the bottom of the openingfz in the base a, andits upperend engages the'shoulder 3 at the upper end of the opening :v-in the table w.

In order to limit. the upward movement of th'` table rw, a set-screw4-the inner end of which is formed with a projection enters the slot Gin the wall of the lpart For the purpose of clamping the table fw, a pin7 is arranged to be forced against the outer wall of the dependingportion of the' table by frictional resistance. To accomplish thispurpose, a set-screw 8 is'employed for exerting the necessary pressureon the pin 7 which engages the depending part From the construction andarrangement ofthe comb-member c and the pointer or conemember /L it willbe seen that the movement of the table lw is at right angles tothe linepassing through the two first-mentioned members. A -A For the purpose ofmeasuring the diam' eter of a thread, the same is inserted between themembers 0 and h, the standard teeth of the comb entering or bearingagainst the walls nit' the thread on one side and the cone-'member IL onthe, other. If the thread bein' measured isV the correct size as.topitch an diameter, the poiriter t willremain at thev middle or zeroposition.A Ii it is over or under size, it will be elevated 0r.depressed accordingly. 'The graduations on the-'scale u may be eitherin millimeters or fractional parts of an inch, as desired.

In using -the measuring gageshown in Figs. 1 and Q, a standard thread isinserted inthe space between the standard comb c and the cone-shapedmember h. The setscrew all is loosened and the milled head f rotated tomove the comb-member c against the standard thread until the 'pointer tstands in the zero position.' T heinstrument 1s now set or adjusted to astandard o r cor-- rect space between the membersc and h. The set-'screwd1 is now tightened. In this carefully adjusted. position the gageisgiven to the workman for testing the diameter and p itch/ of otherscrewthreads,'as taps. When a thread to be tested is inserted, theworkman can instantly determine from Vthe pointer on the scale u whetheror not it is` over o-r under size, and lro\v..',much. It should bestated, in adjusting the gage, that, the tit both as to diameter andpitch between aio the. standard thread, the comb c and cone kis'perfe'ct. By means of this gage an un# skilled workman can readilydetermine the allowable or passable fit of a thread.

In Fig. 3 is shown a slight modification in 35 which, instead of usingcontacts one of which is a 'comb-member'and the other a pointed orconeshaped member, the contacts comprise two combmembers c 'and c2 formewith standard threads-the member c2 being 90 mounted on the movablecone-shaped member h. which moves tthe inter shown in Fig. 1. Themodeiof using this' form of gage is the same as that already described 5under Figs. 1 and 2. The 'advantages in 95 using the two comb-members isthat a larger number of teeth are' brought into engagement with thethread being measured, thus insuring greater accuracy in determining thepitch and diameter of the thread under fconsideration. y

Referringn'ow to thevconstruction shown in Fig. 4, in which two pairs ofcontacts are employed-these contacts are employed when the pitch anddiameter of the threaded 10a. elements to be measured have a pitcheither' longer or shorter than the' standard pitch, and also a diametersmaller than the standard thread. In this ligure the combandcone-members c and h are the same as in Fig. 110 1, and the same ointerconstruction is emplcyed. Below t e Contact members c and l are locateda second pair'of gage members,

in which 3 and 4 are a pair of movable mem- Y bers adapted to be'adjusted by the screws 5 115 and 6 and retainedin their adjustedposition by means of the set-screws 'Hand 81. Located in the member 3 isa groovedroller 9 to receive the threads of the sc'rew-'tojbe imeasured, and located below the members 3 \120 and. 4 is avertical-movable platform w1 that is operated in the same manneras thevplatform w ign Fig. 1.

The manner of operation of the gage shown in Fig. 4 is as follows: Thespace be- 125 vtween the members 3 and 4 is 'adjusted to a minimumdistance i through which the 'smallest sized thread to bemeasuredwcannot pass. That is to sayfit a thread to be measured passesthrough between the members 3 and 4, its diameter is too small and mustbe discarded. The distance between the members c and L is set to receivea thread to lbe measured, that has a'pitch slightly larger than thepitch of the standard thread, While the distance between the members 3and 4 is set to reject a thread whose diaml I eter is too small. Ifa'thread to be measured Asidered passable.

'asses between the members c and i and not etween the members 3 and 4,it is con- If it passes through the space between the fixed members 3and 4, it is considered too small and should be discarded; This form ofgage, therefore, enables unskilled labor to quickly determine whether ornot threaded elements vary in size within the desired limits ofaccuracy.

In using the gages herein, described it is to be understood that therequired pressure that is exerted by the contact members on i thestandard threaded member isone vthat is considered correct, and that thejudgment of the workman on this ypoint 1s entirely eliminated.

Referring to the modification of the calipering deviceshown in Figs. 5and 6, in which a micrometer measuring device is employed insteadof thepointer `construction ,shown in Figs-1 and 2. In this construction thestandard threaded element or comb c and themovable cone-shapedthread-engaging member h are employed. Connected witlligthe member l1,is a micrometer measur .ingjfdevica indicated, as a whole,- by thenumeral 10. A threaded connection between 'che spindle 11 and thethreaded sleeve 12 is made for the purpose of moving the conesha'pedthread engaging member i into contact with the threaded element that isbeing measured, when this threaded element is placed in 'contact withthe standard threaded comb-member c. By means of the micrometergraduations indicated at 13 theexaet size of the finished thread may bedetermined. The construction shown in this modification may be used inthe same manner'as the constructions shown in the other figures. That isto say, the micrometer may beset, or accurately adjusted to a certainaccurate reading on the scale 13, to indicate a definite size thread,as, say, one-half inch. -This reading having been accurately made `vpinadvance byinserting a thread ofstand ard'size between the members e andh, the workman can'then readily determine, when another thread isinserted between these members, how .much it is under or over size,.if'any, when compared with the reading on theA micrometer, thatindicates the correct lsize of, thread. This method is not, of course,'as rapid as that already referred Aconnection with the pointerconstruction shown in Figs. 1 and 2; but it does give the workman,however, a very accurate inz reet size of a thread. By means of theconstruction shown in Figs. 5 and 6, the micrometer would preferably bcs et atthe zero reading and the comb c moved against thc opposite sideof the inserted standard thread until a perfect fit is obtained, or thepermissiblefrictional contact. When another thread is inserted, its sizeas to diameter and pitch, either above or bcloiv the zero reading, couldbe very quickly1 compared with this Zero reading and any variation insize from the standard determined. This construction, therefore, permitsthe accurate sorting of threaded elements. After the micrometer isadjusted, it is not necessary to employ highly skilled labor to makethese readings for sorting the threads.' 'In this modification themovable table 'w is employed,'as in the other figures, and on which thethread to be measured is placed, as already described.

Vhat we claim, is,-

1. A thread-gage, comprising in combination, "a base or supportingmember contact members to engage the ugalls of the threads to bemeasured, one of said members being movable, a pointer-,device operablefrom the movable member, means to iixedly adjust the other member, andmeans to bring the' axis of the thread being measured in the same planeas-the contact members.

2. In a scre\vthread measuring-gage, the combination, of a base-member,thread-receiving members, one of said members being comb-shaped toreceive the threads and the opposite one formed with a cone-'shaped end,means to move the latter member toward the former, means to limitjitsmovement, a pointer, operable connect-ions between the same and thecone-shaped member, and a movable and adjustable table on which thescrew-thread to be measured is placed.

3. In a screw-thread measuring-device to determine its permissiblemaximum and minimum dimensions, the combination, of a base-member, twopair of thread-receiving members mounted therein and arranged one abovethe other, a comb-member on one of the members of the upper pair toreceive the Walls of the thread, the other member of the upper pair ofthread-receiving members being cone-shaped and movable, a groovcd rolleron one of the members of the lower pair, and its opposite or mate beingconeshaped and fixed'.

4. A gageevice for 'measuring screwthreads and comprising, abase-member, an adjustable comb-member to receive and bear against theWalls of the thread to be measured, a movable member designed andarranged to engage the walls of the thread on the opposite side othecomb-member and operable from the .screwthreads being ineasdirectionparallel with the axis of the ured, a pointer movableover a suitablescale thread.

to indicate the size of the thread, an oper- 'FRANK WELLS. ableconnection betweenthe pointer and the FRANKLIN J DGE. mov'able member,'a table-member on which Witnesses:

the thread is placed while being measured, CHARLES N. STODDARD,

and means to adjust the table-member in a J Esm' S. BLACKMER.

